rpmsg: omx: return actual user-provided bytes written in write

rpmsg: omx: return actual user-provided bytes written in write

The 'write' system call is expected to return the number of bytes
written back to userspace. The rpmsg omx driver adds a small packet
header when sending a message to the remote processor, and is
currently returning this header length as well in the driver's write
fop function. This results in the write call always returning more
bytes than what the user has requested. The header length is now
left out of the bytes returned back.

Change-Id: I7132001fbc6fb34d01913bb3c30f455626c91658
Signed-off-by: Suman Anna <s-anna@ti.com>
rpmsg: omx: copy_from_user() errors should return -EFAULT

rpmsg: omx: copy_from_user() errors should return -EFAULT

Change-Id: Ib4a2d92dd3b8afa18e60019871cfea2e6b446a4d
Signed-off-by: David Schleef <ds@ti.com>
rpmsg: omx: return ENXIO in rpmsg_omx_write

rpmsg: omx: return ENXIO in rpmsg_omx_write

The error code, ENXIO is used in rpmsg_omx driver to indicate
a terminal error on the remote processor side. This status is
maintained during the recovery of the remote processor, while
the cdev gets reinitialized/recreated.

The rpmsg_omx's write file operation is currently not returning
this error. This has been added now to have it behave in the
same way as the read file operation.

Change-Id: I61d6e6c07aa39208d913da622ed32d809c51d409
Signed-off-by: Vidhoon Viswanathan <vidhoon@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
rpmsg: omx: fix copy_to_user in register/unregister ioctls

rpmsg: omx: fix copy_to_user in register/unregister ioctls

The ION fd registration and deregistration ioctls has the
arguments reversed in the copy_to_user() calls. The same
has been fixed.

Also included a minor additional case for returning a NULL
ION handle back to user-space.

Change-Id: I9d45957f9b913fa1775e70618f0da82e914a41d6
Signed-off-by: Tyler Luu <tluu@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
rpmsg: omx: send disconnect only if omx state is connected

rpmsg: omx: send disconnect only if omx state is connected

The rpmsg_omx driver sends a disconnect message automatically when the
driver's .release is called. This should be done only if a connection
has been established, otherwise just destroy the local end point.

Change-Id: I21b84aa6d91ae0d456f49cbe958f8e64caf691d5
Signed-off-by: Miguel Vadillo <vadillo@ti.com>
rpmsg: omx: initialize completion event in rpmsg_omx_open

rpmsg: omx: initialize completion event in rpmsg_omx_open

An omx object is created when opening the rpmsg-omx device. However
the "reply_arrived" completion event is not initialized until the
connection message is sent across.

When the rpmsg_omx driver is removed (like in recovery), all pending
threads waiting on the "reply_arrived" are unblocked by a complete_all
call, however, if the rpmsg-omx device was only opened, such event is
not initialized yet, so the complete_all call will dereference a null
object causing a panic.

This patch moves the initialization of the "reply_arrived" completion
event to the open call, after the allocation of the omx object.

Change-Id: I92cf9cf5ac748456cb43bedc88fe1a8d80addd6c
Signed-off-by: Juan Gutierrez <jgutierrez@ti.com>
rpmsg: omx: implement separate register ioctl for sgx buffers

rpmsg: omx: implement separate register ioctl for sgx buffers

This implements a new register ioctl specifically meant for sgx
buffers. rpmsg_omx clients are expected to call register ioctl
for the specific buffer type (ion or sgx) before sending a buffer
to .write for mapping. The registration allows the rpmsg_omx
driver to hold a reference to the ion buffers making up the sgx
buffer, thereby preventing the buffer(s) to be freed up from
under the remote processor.

The individual imported ion handles are expected to be passed
into the .write call.

When a client no longer expects remote processor to use the buffer,
client should call unregister ioctl. A separate unregister ioctl
for pvr buffers is not created, and the same ion unregister ioctl
is expected to be used for all the ion handles a sgx buffer is
comprised of.

Change-Id: Ib36aab90136627899e98717aeb29bfa637ec09fd
Signed-off-by: Tyler Luu <tluu@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>